Certain n-substituted aromatic amidines

ABSTRACT

N-SUBSTITUTED AROMATIC AMIDINES HAVING THE FORMULA   AR1-C(=NH)-NH-AR3   IN WHICH AR1 IS AN UNSUBSTITUTED PHENYL RADICAL OR A PHENYL RADICAL SUBSTITUTED BY A HALOGEN ATOM, A METHOXY RADICAL OR A TRIFLUOROMETHYL RADICAL; AN UNSUBSTITUTED OR SUBSTITUTED NAPHTHYL RADICAL OR A PYRIDYL RADICAL; AND AR2 IS AN UNSUBSTITUTED PHENYL RADICAL OR A PHENYL RADICAL SUBSTITUED BY ONE OR MORE HALOGEN ATOMS, E.G. CL, BR OR F, BY A TRIFLUOROMETHYL RADICAL, BY ALKYL RADICALS HAVING 1 TO 4 CARBON ATOMS, OR BY ONE OR MORE ETHER OXIDE GROUP O-R, WHERE R=-CH3,-C2H5 OR -C3H7; AN UNSUBSTITUTED OF SUBSTITUTED NAPHTHYL RADICAL OR A HETEROCYCLIC RADICAL, SUCH AS A PYRIDYL RADICAL. A PROCESS FOR OBTAINING THE AMIDINES COMPRISES REACTING AN AROMATIC AMINE WITH AN AROMATIC NITRILE USING AN ALKALINE AMIDE AS A CONDENSATION AGENT AND BY CARRYING OUT THE REACTION IN LIQUID AMMONIA. THE AMIDINES HAVE THERAPEUTIC ACTIVITY AS ANALGESICS, AS ANALGESICS, ANTI-INFLAMMATORY AGENTS, NEUROSEDATIVE OR PSYCHOANALEPTIC AGENTS, ANTIPYRETIC AGENTS, ANTI-HYPERTENSIVE AGENTS AND HYPOTENSIVE AGENTS.

United States Patent 01 iice 3,632,593 Patented Jan. 4, 1972 3,632,593 CERTAIN N-SUBSTITUTED AROMATIC AMIDINES Jean Albert Gautier, Marcel Miocque, and Claude Fauran, Paris, and Albert Yves Le Cloarec, Saint-Maur, France, assignors to Dilalande S.A., Courbevoie, Hauts-de- Seine, France No Drawing. Filed July 9, 1968, Ser. No. 743,332 Claims priority, application Great Britain, July 14, 1967, 32,426/67 Int. Cl. C07d 31/42 US. Cl. 260-296 R 2 Claims ABSTRACT OF THE DISCLOSURE N-substituted aromatic amidines having the formula in which Ar is an unsubstituted phenyl radical or a phenyl radical substituted by a halogen atom, a methoxy radical or a trifluoromethyl radical; an unsubstituted or substituted naphthyl radical or a pyridyl radical; and

Ar is an unsubstituted phenyl radical or a phenyl radical substitued by one or more halogen atoms, e.g. Cl,

Br or F, by a trifiuoromethyl radical, by alkyl radicals The present invention concerns new N-substituted aromatic amidines and a process for obtaining same.

The new compounds of the present invention correspond to the general formula:

in which Ar is an unsubstituted phenyl radical or a phenyl radical substituted by a halogen atom, a methoxy radical or a trifluoromethyl radical; an unsubstitued or substituted naphthyl radical or a pyridyl radical; and

Ar is an unsubstituted phenyl radical or a phenyl radical substituted by one or more halogen atoms, e.g. Cl, Br or F, by a trifluoromethyl radical, by alkyl radicals having 1 to 4 carbon atoms, or by one or more ether oxide groups OR, where R=CH C H or C H an unsubstituted or substituted naphthyl radical or a heterocyclic radical, such as a pyridyl radical.

Various methods are known for obtaining amidines which, in general, utilize high temperatures and reactants such as aluminum chloride or sodium, which exert a degradative action on the various substituents of the aromatic or heterocyclic nuclei.

The process for obtaining the new amidines forming the object of the present invention in high yields is based on a new method of preparation of N-substituted amidines which comprises reacting an aromatic amine with an aromatic nitrile, using an alkaline amide (most frequently sodium amide) as condensation agent and by carrying out the reaction in liquid ammonia. This method may be represented by the following equation:

NaNHz ATr-CNII-Al2 I IH wherein Ar and Ar are as defined above.

The general method of preparation of the compounds according to the present invention is as follows:

0.1 mol of the amine Ar -NH (in solution in 30 ml. of anhydrous ether or not) is added to a suspension of 0.1 mol of sodium amide in 300 ml. of liquid ammonia. After agitation of the mixture for 3 hours, the nitrile Ar CEN (in solution in anhydrous ether or not) is added. Agitation is continued under reflux for 3 hours. Then 0.1 mol of NH Cl is added and the ammonia is removed by evaporation. The dry residue is taken up in 150 ml. of water and extracted three times with ether. After evaporation of the solvent, a solid crystallized residue is obtained.

The amidines obtained, when dissolved in an organic solvent and treated with a mineral or organic acid, give crystallized salts having definite melting points.

The following non-limitative examples illustrate the preparation of the present invention.

EXAMPLE 1.N- (m-fluorophenyl -benzamidine Several crystals of ferric nitrate are added to 300 ml. of liquid ammonia and then 0.1 atom gram of sodium (2.3 g.) is gradually added thereto and the mixture is agitated until the complete formation of sodium amide is achieved (grey suspension). Then 0.1 mol of m-fluoro aniline is added thereto and after 3 hours under agitation 0.1 mol of be'nzonitrile is added. The mixture is agitated under reflux for 3 hours.

Then 0.1 mol of ammonium chloride is introduced into the mixture and the ammonia is removed by evaporation. The residue is taken up in 100 ml. of water and extracted three times with ether. The ether extract, on evaporation, gives a brown crystallized residue.

Recrystallization is effected in an acetone-petroleum ether mixture.

Yield=%. Melting point =99 C.

Elementary analysis.Calculated (percent): C, 72.88; H, 5.17; N, 13.08; F, 8.87. Found (percent): C, 73.03; H, 5.11; N, 13.00; F, 9.05.

EXAMPLE 2.-N-(3,4-dichlorophenyl) o-chlorobenzamidine 0.1 mol (16.2 g.) of anhydrous 3,4-dichloroaniline is added to a suspension of 0.1 ml. of sodium amide in 300 ml. of liquid ammonia. The mixture is of a green colour and is agitated for 3 hours. Then 0.1 mol (13.7 g.) of o-chlorobenzonitrile is added and the mixture is agitated under reflux for 3 hours and the mixture turns black. After adding 0.1 mol of ammonium chloride and evaporating the solvent, the residue is taken up in 100 ml. of water and is extracted with ether. The ether extract is evaporated and a brown crystallized residue is obtained, which is recrystallized in petroleum ether.

Yield=74%. Melting point=l22 C.

Elementary analysis.--Calculated (percent): C, 52.11; H, 3.03; N, 9.35. Found (percent): C, 52.08; H, 3.23; N, 9.47.

EXAMPLE 3 .-N- (p-chlorophenyl) a-naphthamidine 0.1 mol (12.7 g.) of p-chloroaniline is added to a suspension of 0.1 mol of sodium amide in 300 ml. of liquid ammonia. The mixture is green in colour and after 3 hours under agitation 0.1 mol (15.3 g.) of a-naphthonitrile is added thereto. The mixture is agitated under reflux for 3 hours. The mixture is then treated with ammonium chlo- 3 ride, the solvent is evaporated, the residue is taken up in Water and then extracted with ether.

The ether extract, after evaporation yields a crystallized residue which is recrystallized in an acetone-heptane TABLE III mixture. 5 NH Yield=82%. Melting point=158 C. Elementary analysis.Calculated (percent): C, 72.72; H, 4.67; 9.98. Found (percent): C, 72.79; H, 4.65; N, N Melting Melting point, Yield, point,

EXAMPLE 4.--N-(3,4-dichlorophenyl)- 0 0 m-pyridylamidine O-OCH3 HCBH4 16.2 g. of 3,4-dichloroaniline is added to a suspension 113 of 0.1 mol of sodium amide in 300 ml. of liquid ammonia gzg 'ggfiyfg fig: E2 and after 3 hours under agitation 10.4 g. of rn-cyano- 3,4,5-lSI OCH3-CGHL- 172 pyridine is added thereof. giggjggt The reaction is continued for a further 3 hours. After p-CH3C&H4 127 the addition of ammonium chloride to the mixture and evaporation of the solvent, 200 1111. of water is added; a precipitate is formed which is dried and Washed with water. After drying the precipitate is recrystallized in an ethyl acetate-petroleum ether mixture.

Yield=83%. Melting point=202 C. Elementary analysis.Calculated (percent): C, 54.15; H, 3.41; N, 15.79; 01, 26.65. Found (percent): 0, 54.19; TABLE W H, 3.54; N, 15.60; Cl, 26.64.

-CNHAr,, EXAMPLE 5.--N-(4-n1ethylphenyl)- N Q m-pyridylamidine To a suspension of sodium amide in liquid ammonia 1353 Yield t prepared as above, 10.7 g. of p-toluidine is added, and Ari o percem; salt prepared L after 3 hours under agitation, 10.4 g. of m-cyanopyridine 4 l is added thereto. After having effected the same treatment tr E 3% as described in Example 4, the precipitate is dried, which 172 69 10s as after washing and drylng 1s recrystalllzed in an ethyl 143 77 acetate-petroleum ether mixture. glield=57%. Melting 3011 17 157; 0. 6 g io ei a oint;

ementary ana ysis.-Ca cu ate (percent): C, 73.5 1 a 3 014.0110 H 194 78 Dlh 1 n1 id H, 6.17; N, 20.27. Found (percent): 0, 73.68; H, 6.27; e -6.6L? 157 Y m 8 N, 20.09.

The compounds appearing in the following tables have been prepared by the process described and illustrated in the above examples.

TABLE I Nl-I TABLE V Melting Melting N i point, Yield, point, H Ar; percent Salt prepared C. NH

99 Hydrochloride..- 200 g? 175 Melting Melting 108 point, Yield, point,

92 Ar; percent Salt prepared 11o GlC H 133 i'h-F-OZHZ-.. 122 m-CFzCsH4 152 0OCHsCsH1 125 TABLE I1 oem-c3114... 14s a-Naphth 12:: Cl B-Naphthyl. 14s 61 I 3Cl4.CH3C3H3 65 Dihydroehloride 215 60 2,5-dIOC 3C6 103 71 -C-NH.AT2 3,4-dlOl-C6H3 63 H o-OH-OsH1 171 NH 06 5 p-CH3C6H4 126 M lilting Melting point, Yield, point, Ari 0. percent Salt prepared C. 9

p-Cl-C1H4 127 n1-FCsH4 105 :m-CF3CH4 90 0-0 CH3-COH4 90 p-O CH3CsH4 122 aNaphthyl 110 jgfiPg%- The compounds of the present invention have been 2,5-(1100H3-0i1l3--. 139 66 a tested on animals in the laboratory and it has been found i ijgf ifggfgtm 1 Z4 1: f: that these compounds possess a therapeutic activity. 06m 10% 87 Hydrochlorid 73 Thelr DL 50 has been found to be completed with their P'CHFCGHL 53 75 pharmaceutical usage as shown in the following table.

Lethal dose Compounds of Formula I 50 in mgJkg. determined Al? on mice 111-0 Fa-CaEL: 580 3,4=-diCl-CH 760 m-CFsCaH4 1000 -0 CH3-C5H4 200 3,4-diCl-C6H3 1000 m-F-CsHa 760 p-C1-C&H4 1000 Ill-CFr-CGH4 1000 3 ,4-di Cl C 6H3 3000 m-CF CH4 910 p-Cl-CtH4 230 p-Cl-CaHr 1000 The compounds of the present invention have shown: (a) an analgesic action studied by according to the method of Siegmund (E), Cadmus (R) and Go Lu (Proceedings of the Society of Experimental Biology and Medicine, 1957, volume 95, page 729) which shows itself by an inhibition of the painful stretching caused by the intraperitoneal injection of phenylbenzoquinone;

EXAMPLES Dose admin- Compounds istered, Protection, studied lug/kg. percent No. 20 50 No. 200 43 N0. 100 52 N0. 100 40 No 120 50 No 90 50 No. 90 50 N0. 20 40 N0. 200 40 (b) an anti-inflammatory action studied according to the method of Winter (C. A.), Risley (E. A.) and Nuss (G. W.) (Proceedings of the Society of Experimental Biology and Medicine, 1962, volume 111, page 544) which shows itself by an inhibition of the Oedema under Plantar release caused by the local injection of carragenine on the rat;

EXAMPLES Dose admin- Compounds istered, Protection, studied rug/kg. percent istered, rug/kg.

Compounds studied Augmentation of 45%. Diminution of 46%. Diminution of 50%.

(2) by the measurement of the motility in a meter device having photoelectric cells;

Example Compound studied: No. 9.

Dose administered: mg./l g.

Effect: Hypomotility 50 percent.

(3) by the potentialisation of pentothal;

Compound studied: No. 9.

Dose administered: mg./kg.

Potentialisation: 50 percent.

(d) an antipyretic action studied according to the technique of Benza (G), Crema (A) and Pausse Pesce (A) (Farmaco 1966, volume 21, page 485) which shows itself by an inhibition of the fever caused by the intramuscular injection of a suspension of balm on the rat;

(e)- an antihypertensive action observed on a rat rendered hypertensive by 'a renal or perinephritic cellophane ligature or an overdose of desoxycorticosterone acetate with unilateral nephrectomy, and

(f) a hypotensive action observed in the rat, rabbit, cat and dog which is manifested by a progressive and durable tensional fall.

EXAMPLE Dose administered Compound studied provoking a prolonged Ar; Alz hypotension 1 mg./kg./IV

p-CHa-CaI-Ii What we claim is: 1. A compound of the formula in which Ar and Ar are radicals selected from the respective groups tabulated below and used in the combinations of Ar and Ar as tabulated below.

1. Trifluoromethylphenyl, 3,4dlchlorophenyl,

2,5-dimethoxyphenyl, 3,4,5-trimethoxyphenyl and 3-chloro4methylphenyl.

2. Chlorophenyl and 2. Trifiuoromethylphenyl, 2,5-dimethoxyphenyl, 3-pyridyl. 3,4,5-trimethoxy phenyl, 3,4-dichloropl1enyl and 3-chloro-4-methylphenyl, phenyl substituted with an alkyl radical having 1 to 4 carbon atoms, phenyl substituted with an alkoxy radical having 1 to 3 carbon atoms, a-naphthyl and B-naphthyl.

4. a-naphthyl 4. Trifluoromethylphenyl, hydroxyphenyl,

halogen-substituted phenyl, 2,5-dimethoxyphenyl, 3,4,fi-trimethoxyphenyl,3,4-dichlorophenyl and 3-chloro-4-methylphenyl.

1. Phenyl and the pharmacologically acceptable acid addition salts thereof.

8 2. A compound according to claim 1 in which Ar is Robev, Chem. Abstracts II, vol. 55, p. 18676 (1 961).

Misra et a1. Chem. Abstracts III, v01. 57, p. 4609 3-pyridy1 and Ar is 3,4-dichlorophenyl.

(1962). Chem. Abstracts 1V, v01. 65 pp. 10577-10578 References Cited (1966),

Klingsberg, Pyridine and Derivatives, Part 3, Inter- 5 science (1962) pp. 27, 28, 147 and 14s. ALAN ROTMAN, Prlmary Examlner (lgggiiwm et a1. Chem. Abstracts, v01. 39, p. 4396 Us. CLX'R' Sidgewicks Organic Chemistry of Nitrogen, Oxford, 260564 999 3rd ed. p. 245 (1966). 1D 

